The invention concerns a window lifter with a guide rail affixed on a base part.
It is generally known to affix guide rails of a window lifter, in which rails the window pane is driven along its closing and opening movement, on a base part. The base part is usually designed as a door inner panel or an assembly carrier. The guide rails are screwed, riveted, or welded or attached by snap elements to this base part. The guide rails rest on the base part with a flat face.
Disadvantageous in such connections is the fact that because of the fixed mounting of the guide rails on the base part, subsequent alignment of the guide rails is not possible, such that stresses may develop inside the window lifter system.
From DE 196 11 074 A1, an arrangement for the adjustment of a frameless window pane by a tilting motion at right angles to the longitudinal axis of the motor vehicle is known, wherein separate adjustment and locking means are provided for each guide rail. One of the guide rails is equipped with a slotted guide and the other guide rail has an adjustment screw, which is equipped with a self-locking thread. The guide rail with the slotted guide is first affixed loosely on the base part. By rotation of the adjustment screw, the guide rail is pivoted at a right angle to the longitudinal axis, and this rotational movement is transferred by the window pane to the guide rail with the slotted guide such that the position of the two guide rails as well as the window pane changes uniformly.
Such an arrangement does enable the adjustment of the window pane by a tilting motion; however, the coordination of the guide rail seat with the base part is only imprecisely possible since the two assemblies are placed only loosely on each other. Stresses due, for example, to twisting guide rails because of manufacturing inaccuracies cannot be compensated by this type of attachment or adjustment. Likewise, an adjustment of the guide rails with spherically curved window panes is difficult.
The object of the invention is to provide a window lifter with a guide rail affixed on a base part, which is simple and precise to adjust and which prevents stressing of the window lifter system.
The design of the seat and a corresponding mating part enables tilting without the guide rail and the base part being able to be displaced relative to each other. On the one hand, this makes possible the adjustability of the guide rail for exact, problem-free operation of the window lifter, since a specific affixing of the window pane has already occurred; on the other, no unwanted tilting or displacement of the rail occurs such that, overall, assembly accuracy is increased and assembly time is reduced.
An improvement of the invention provides that the seat and the mating part prevent displacement of the base part and the guide rail relative to each other in at least one direction, for example, by means of a cylindrical design of the seat and of the mating part, whereby the seat and mating part oppose each other in a mirror image. Thus, unwanted tilting around a specific axis can be prevented, whereby the accuracy of the assembly is rendered easier in those cases in which no adjustment around multiple axes must be made.
Through connection of the guide rail with the base part by means of a ball-cup mating it is possible to rotate the guide rails of the window lifter in multiple directions such that an exact adjustment of the guide rails can occur and no stresses occur within the window lifter system. Especially in the case of highly curved window panes, adjustability in multiple directions, which is accomplished by means of a ball-cup mating of the guide rails with the base part, is necessary.
In one embodiment of the invention, at least one ball- or cup-shaped seat is arranged on the base part or on the guide rail. By means of this seat, the ball-cup mating is realized, and a movable connection between the guide rail and the base part is permitted. For technical production reasons, it is advantageous to design this seat in one piece on the base part, for example, by an appropriate shaping process, such as deep drawing or pressing. It is possible to produce the seat already at the time of production of the base part in a molding operation such as casting or injection molding.
In an advantageous embodiment, the seat is designed as a cup-shaped recess in a conical or spherical projection. Thus, a base for the cup-shaped recess is more or less formed, yielding a relatively large radius of motion of the component (base part or guide rail) with the cup-shaped recess relative to the ball-shaped mating part. The conical or spherical projection in which the cup-shaped recess is formed can be formed on either the base part or the guide rail. The projection can likewise be formed in the guide rail or the base part in a shaping or molding operation.
As an alternative to the ball shape of the seat, provision is made to design the seat and, accordingly, the mating part as a barrel-shaped or cylindrical shape, whereby the seat has the mirror-image shape of the mating part. The adjustability of the guide rail can be realized with one of the mating pairs either through a combination of a ball-cup mating with a cylinder-mounting or by an adjustment arrangement on an attachment region of the guide rail, for example, by an adjustment bolt with a check nut.
Advantageously, a through-hole, through which an affixing means can be passed, is provided in the seat to enable an appropriate connection of the base part with the guide rail. The through-hole is formed either on the guide rail or on the base part and is advantageously provided as an oblong slot, thus yielding an increased adjustment range of the guide rail in the direction of the lengthwise path of the oblong slot. It is also possible to select the cross-section of the through-hole substantially larger than the cross-section of the affixing means such that there is increased movability of the guide rail relative to the base part in all directions. In the selection of the cross-section of the through-hole, consideration must be given to the fact that the guide rail is attached to the base part by the affixing means.
By designing the affixing means as a releasable connecting element, for example, as a screw, simple adjustment of the position of the guide rails relative to the base part is possible. Likewise, this makes it possible to perform subsequent adjustment or, in the event of repair or damage to the window lifter system, readjustment of the guide rails.
In an advantageous embodiment, the affixing means has a contact zone adjacent the base part and a contact zone adjacent the guide rail, whereby the respective contact zones are designed corresponding to the seat of the base part or of the guide rail. If, for example, the base part is designed flat, the corresponding contact zone is also designed flat. With a ball-shaped design of the base part or of the guide rail, the contact zone is, accordingly, cup-shaped to accommodate the ball-shaped zone of the guide rail or of the base part. The contact zones are shaped such that the guide rails can swivel relative to the base part.
In one embodiment of the invention, the affixing means is designed as an affixing screw which is connected only by at least an affixing nut with the base part and the guide rail. It is advantageous in this case if the affixing nut has a ball- or cup-shaped head corresponding to the seat of the base part or of the guide rail. This ensures that the head of the affixing nut comes into full-surface connection with the correspondingly shaped seat.
In a variant of the invention, the affixing means is nonreleasably connected with the guide rail, for example, by welding, soldering, or by extrusion. This reduces the number of parts that are necessary to affix or assemble the guide rail to the base part. In an improvement of the invention, the affixing means is designed as a threaded segment on which a curved contact zone is connected. This contact zone serves as a ball- or cup-shaped seat and enables an appropriate displacement of the correspondingly designed mating part. Provision is made, for example, to design the contact zone ball-shaped on the guide rail and to realize a cup-shaped seat of the base part such that the guide rail and the base part can the swivel in multiple planes.
Provision is further made that the mating part and the affixing means form one assembly unit such that the mating part does not have to be designed in one part in the guide rail, but instead can be produced and mounted separately, for example, as a special screw. This is especially advantageous if the mating part must have special hardness and thus must be made from a different material.